获取具有不同数组的字段的最低值

I have created the following array in PHP with help of the Google Distance Matrix API.

Now I need to compare the [distance] field, get the lowest value and save the key of the array in a variable. How do I do this? I looked at min() but this doesn't seem to work with multiple arrays.

Array
(
[utrecht_cs] => Array
    (
        [name] => utrecht_cs
        [address] => 3511 AX Utrecht, Netherlands
        [distance] => 95
    )

[groningen_cs] => Array
    (
        [name] => groningen_cs
        [address] => 9726 AC Groningen, Netherlands
        [distance] => 102.47
    )

[zwolle_cs] => Array
    (
        [name] => zwolle_cs
        [address] => 8011 CW Zwolle, Netherlands
        [distance] => 2.54
    )

)

You could use uasort() to sort your array. Then, you could get the first key using key().

$array = array(
    'utrecht_cs' => array(
        'name' => 'utrecht_cs',
        'address' => '3511 AX Utrecht, Netherlands',
        'distance' => 95
    ),
    'groningen_cs' => array(
        'name' => 'groningen_cs',
        'address' => '9726 AC Groningen, Netherlands',
        'distance' => '102.47'
    ),
    'zwolle_cs' => array(
        'name' => 'zwolle_cs',
        'address' => '8011 CW Zwolle, Netherlands',
        'distance' => '2.54'
    )
);

uasort($array, function($a, $b) { return $a['distance'] <=> $b['distance']; });
$first_key = key($array);

Output:

zwolle_cs

You can also use (for PHP version before 7.0):

uasort($array, function($a, $b) { 
   return $a['distance'] < $b['distance'] ? -1 : 1; 
});

You want to use usort to sort your multidimensional array.

http://php.net/manual/en/function.usort.php

function sortNumbers($a, $b)
{
    return $a['distance'] <=> $b['distance'];
}

usort($yourArray,'sortNumbers');

Read this for more info https://delboy1978uk.wordpress.com/2012/09/19/sorting-multidimensional-arrays-using-php/

An alternative sorting. Extract the distance column from the array and sort on that, sorting the original array based that:

array_multisort(array_column($array, 'distance'), $array);
$result = key($array);